1. Field of the Invention
The field of the invention is that of remote analysis and correction of crop condition, namely through a sophisticated system of data collection, computer analysis and remote irrigation response that includes status alerts to the end user. In the disclosed method and system, crop condition is remotely monitored and managed by collecting and analyzing multiple streams of data, including crop characteristics which may include biologic and environmental variables. The data is transmitted to a server where it is correlated with customized algorithms that may include economic variables in order to computer formulate an irrigation decision which is then executed manually or remotely by the end user or in an automated fashion by signal to the irrigation field base station.
2. Description of Related Art
In the United States, 80% of all fresh water consumed is for irrigation. Of that amount, 70% is used for agriculture. The United States uses nearly 83 trillion gallons of water annually to irrigate some 53 million acres. The majority (44%) of irrigated acreage utilizes gravity fed or “flooding” techniques. Center pivot irrigation commands an additional 41%. Drip irrigation is the slow application of water directly to the root area of the plant and is used 5% of the time. It provides a 95% to 99% applied water efficiency, much higher than either gravity fed or center pivot methods.
Even with drip irrigation, however, there remains a tendency to overwater. Using only visual or indirect means to analyze plant condition, the grower lacks sophisticated or timely enough data to accurately decide when to initiate or cease irrigation. Even if he were to make an educated guess as to the number of hours of watering his crop required, his estimated water need will fluctuate widely during the watering time, as a result of environmental variables such as rain, ambient temperature, relative humidity, wind speed and crop need.
In addition, growers are not always available to manually assess crop condition and start, stop, or adjust irrigation. Although limited technology exists to “remote start” irrigation systems, these technologies are cost prohibitive for most growers and limited in application. They lack data collection, data transmission, computerized correlation with algorithms, irrigation decision formulation and real time remote or automated execution. Although a few remote monitoring and irrigation systems exist, they are designed for residential or commercial sprinkler system use, rather than commercial agriculture. Even with a “remote start” system the grower must still physically visit his fields and make the subjective determination of whether it is prudent to water. This handicaps the grower's ability to build the business.
As an example of the limiting nature of current systems, if it rains during the night while the irrigation is running, the crops are likely overwatered by the time the grower wakes up and takes action. Even if the grower is sophisticated enough to use soil moisture sensors or other methods, he still must interpret the information, formulate a decision as to whether to irrigate and then be present to manually start and stop his system.
There are three methods of assessing a crop's condition: visual, indirect and direct. Visual observation is subjective at best and requires the grower to wait for physical signs of plant deterioration before adjusting the irrigation schedule. This waiting period causes the crop to experience significant and otherwise preventable stress. Methods of indirect measurement include soil moisture sensors, calculation of evapotranspiration or atmospheric parameters. These techniques require considerable time, cost and effort and still fail to give a comprehensive assessment of the plant's water needs. Direct measures such as measuring stomatal resistance exist but are costly and destructive to the plant. Studies increasingly reveal the value of calculating a crop water stress index (CWSI) and scheduling irrigation accordingly to minimize the plant's stress and optimize growth (or blooming or other characteristics desired by the grower). To calculate CWSI effectively though requires direct measurement of the plant's water status, preferably with real time reporting to ensure rapid response to the crop's earliest changes.
Upchurch et al., (U.S. Pat. No. 5,539,637, issued Jul. 23, 1996) developed a process for making irrigation decisions for crops based on crop canopy temperature measurements. Research has shown plants exhibit optimum enzyme function when their temperature stays within a specific thermal kinetic window. Burke et al. (1988, Agron. J., 80:553-556). Mahan and Upchurch later proposed that plants have a preferred temperature range and that maintenance of this temperature range requires the plant to have sufficient energy input to raise temperature, sufficient water to lower temperature, and a humidity range that allows for transpirational cooling. Mahan and Upchurch (1988, Envirn. and Exp. Botany, 28:351-357).
Based on these and similar studies, Upchurch et al developed a method for determining under what circumstances additional water would be effective to lower a plant's temperature to achieve the optimum thermal kinetic window. (U.S. Pat. No. 5,539,637, issued Jul. 23, 1996). In the Upchurch patent, only crop canopy temperature, air temperature and humidity are measured. These measurements are incorporated into formulas to determine the plant's level of thermal induced stress and what length of time the plant has been overstressed. The measurements are compared to predetermined optimal temperatures for the specific plant variety and, if warranted, an audible or visible signal is generated. The operator can review the data and signal and decide to manually begin irrigation. (U.S. Pat. No. 5,539,637, issued Jul. 23, 1996).
The Upchurch patent was a significant breakthrough due to its capability to directly, rather than indirectly, measure a plant's water needs without being invasive or destructive. Since the granting of the Upchurch patent, more types of biological data have become important to determine irrigation decisions. Although the Upchurch method of collecting canopy temperature, humidity and air temperature is still good science, a grower needs to be able to use other biological, environmental and even economic data to more specifically control crop growth and production, and, more importantly, to do so with minimal use of water.
There is also a need for the grower to access historical data of his crop water status and treatments. Farming has progressed to a highly technical science, where biological characteristics of the plant, environmental conditions, expected environmental forecasts and even such data as market changes, utility costs and water restriction laws must be considered to reach prudent watering decisions. It is highly time-consuming and burdensome for the grower to collect all these various types of data, timely correlate an irrigation schedule and then manually adjust his irrigation method as needed on a real time basis.
As the cost of fuel and electricity to pump water rises, the grower is incentivized to implement specific watering strategies. The water efficiency of systems such as drip irrigation could be vastly improved by incorporating more sophisticated methods to determine when and how much to water. There is a need for a system capable of cost effectively collecting and analyzing multiple sets of data to determine crop condition, long before visual signs of over or under watering manifest.
There is a need for sophisticated methods to determine crop condition and the crop's precise water needs. There is a need for a simple and cost effective means whereby the grower can monitor and control the performance of an irrigated crop from the convenience of his office or home. There is a need for an improved method and system to automate the process of determining when it is prudent to irrigate and executing that decision.